In recent years, because of their potential application in all manner of fields, techniques for fabricating microscopic structures have been the subject of intensive research and development. For example, structural bodies that include structures of nanometer size (so-called nanomaterials) exhibit different physical and chemical properties from their corresponding bulk materials, and are therefore attracting enormous interest, both from the fundamental research perspective and the applied research perspective. For example, nanomaterials having a hollow three dimensional structure such as a cylindrical shape are expected to have important roles in a variety of different fields, including inclusion chemistry, electrochemistry, materials science, biomedicine, sensors, catalysts and separation techniques. Furthermore, techniques for fabricating line-shaped micropatterns can be linked directly to the fabrication of integrated circuits and increased integration levels, and are therefore the subject of extremely intensive research and development in fields such as the semiconductor industry.
Conventional methods of producing microscopic structures include methods known as template methods, and methods that use lithography techniques. For example, Non-Patent Document 1 proposes a method of producing a nanomaterial having a spherical capsule-shaped hollow three dimensional structure by dispersing template microparticles in a solution, coating the surface of the template microparticles with a thin film, and then removing the template microparticles.
Further, the applicants of the present invention have proposed methods of producing nanostructures by coating the surface of a template having a nanopattern formed thereon with a coating film or a composite film of a metal oxide and an organic compound, and then removing the template (see Patent Documents 1 and 2).
Furthermore, methods of fabricating microscopic metal structures are also known, including (1) methods in which a lithography technique is used to form a microscopic pattern on top of a metal layer, and that microscopic pattern is then used as a mask for etching the metal layer, and (2) methods in which a metal plating technique is used to fill a microscopic pattern formed using a lithography technique.    [Non-Patent Document 1] Advanced Materials, 13(1), pp. 11 to 22 (2001)
[Patent Document 1]    Japanese Unexamined Patent Application, First Publication No. 2005-205584
[Patent Document 2]    Japanese Unexamined Patent Application, First Publication No. 2006-297575